Reversible variable pitch propeller



March 1, 1932. G THOMAS v 1,847,502

- REVERSIBLE VARIABLE PITCH PROPELLER Filed Feb. 8, 1930 3 Sheets-Sheet 1 I z z 20 /9 7'- any T/wmas 3mm March 1, 1932. G. THOMAS Q I 1,847,502

I REVERSIBLE VARIABLE PITCH PROPELLER Filed Feb. 8, 1930 '3 Sheets-Sheet 2 as, I

March 1, 1932. G THOMAS 1,847,502

REVERSIBLE VARIABLE PITCH PROPELLER Filed Feb. v8, 1930 3 Sheets-Sheet 3 Patented Mar. 1, 1932 UNITED STATES GUY THOMAS, 015 SAN ANTONIO, TEXAS REVERSIBLE VARIABLE PITCH PROPELLER Application filed February 8, 1930. Serial No. 427,023.

One object of this invention is to provide means whereby the angle of the propeller blade of an airplane can be changed during the flight of the machine at any altitude, it

being possible, thus, to allow for varying resistances of the air at different altitudes.

A further object of this invention is to provide a means whereby the angle of the propeller blades may be completely reversed, so

that the blades will act as a brake, the time required for landing being shortened, and a means being afforded whereby the propeller blades, having been reversed, will operate to lessen the force of a downward movement,

when the plane is out of control, due to some cause other than engine trouble.

A still further object of the invention is to provide a means whereby one or both propellers may be readily removed, and be replaced by others of equal balance.

It is within the province of the disclosure to improve generally and to enhance the utility of devices of that type to which the present invention appertains.

With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes may be made in the precise embodiment of the invention herein disclosed, within the scope of what is claimed, without departing from the spirit of the invention.

In the accompanying drawings:

Figure 1 is a plan of one form of the invention, parts being broken away;

Figure 2 is a longitudinal section, with parts in elevation;

Figure 3 is a cross section on the line 3-3 of Figure 1; I

Figure 4 is a longitudinal section of a modification, with parts in elevation,

Figure 5 is a longitudinal section of another modification, parts being in elevation Figure 6 is a sectional view showing another modification, parts being in elevation.

In Figures 1, 2, and 3, there is shown a support including a casing 1 made up of separable members held together by securing elements 2, the casing having a transverse stem 3 provided with a flange 4 connected by .securing members 5 to a flange 6 on the engine shaft 7. Tubular shafts 9 are arranged in c0- axial relation,at right angles to the engine shaft 7 and to the stem 3 and are journaled in the casing 1, the shafts being provided with beveled gears 8 located within the casin 1, the shafts 9 having disc-like heads 16 that bear against opposed portions of the casing 1, internally thereof. The shafts 9 are provided with flanges 10 connected by securing devices 11 to flanges 12 on the propeller blades 14. A reinforcement 15,in the form of a rod, has its ends located in the propellers, the member 15 extending through the flanges 12, the flanges 10, the tubular shaft 9, the heads 16, and the beveled gears 8. The rod or reinforcement 15 is not secured'in place, aside from the fact that the parts in which it is mounted prevent it from moving either longitudinally or transversely.

Short auxiliary shafts 17 are journaled in the casing 1 and are disposed at right angles to the axis on which the propeller blades 14 turn for adjustment, that axisb'eing repre sented by the axis of the reinforcing rod 15. Beveled pinions 18 are secured to the inner ends of the shafts 17 and mesh with the bevs eled gears 8. Arms'19 are secured to the shafts 17 externally of the casing 1. Links 20'are pivoted to the arms -19 and are pivoted to a slide 21in the form of a ring mounted for reciprocation on the stem 3 of the casing 1 35 and held thereon, for right line movement, by

a key 22 or equivalent device. The slide ring 21 has a peripheral groove 23, whereby the slide ring is journaled in the bearing 24, which may be a ring, the member 24 having an arm 25 which is pivoted to an operating means 26.

The engine shaft 7 causes the propeller blades 14 to operate in the usual way, the slide 21 rotating in the ring 24. By means the operating device 26, the ring 24 and the ring 21 can be shifted lengthwise of the member 3, the links 20 and the arms 19' rocking the shaft 17, the pinions 18 rotating the gears 8, the shafts 9, and the blades 14, about an axis at right angles to the axis of the .engine shaft 7, the pitch of the blades 14 being adjusted, thus, at the will of an operator.

In Figure 4, the casing or support 27 has a stem or shaft member 28 on which the slide 29 is held for right line reciprocation, the slide being grooved at 30 to receive the bearing ring 31 in which it turns. The operating mechanism 33 is connected pivotally to an 10 arm 32 on the ring 31. Links 34 are pivoted to the slide 29 and to the outer ends of crank arms 35 secured to shafts 36 arranged at right angles to the axis of the stem 28 and journaled in bearings 37 projecting inwardly 5 from the casing 27. Pinions 38 are secured to the inner ends of the supplemental shafts 36 and mesh with larger gears 39 keyed at 40 to main shafts 41 that are disposed parallel to the shafts 36 and at right angles to the 0 shaft or stem 28. The main shafts 41 preferably extend out into the butts of the propeller blades 42. The blades 42 have flanges 43 attached by securing devices 44 to flanges 45 on tubular shafts 46 that are journaled in the casing 27. Each shaft 46 has a head 47 that bears against the inside of the casing 27.

The main shafts 41 extend through thetubu lar shafts 46. and are keyed to them at 48. The propeller blades 42 are rocked to change their pitch, about an axis at right angles to the engine-driven shaft 28, by a train of parts comprising the operating mechanism 33. the arm 32, the bearing 31, the slide 29, the links 34. the crank arms 35, the supplemental shafts 36, the pinions 38, the gears 39, the main shafts 41, the tubular shafts 46. and the connected flanges 4543.'

It is noted that the device of Figure 4 is unbalanced as to the links 34. and to prevent undesirable vibration that might result from such a construction, it is understood that a suitable counterbalance of weight. properly placed to correct the aforesaid lack of balance. is to be provided in the finished device. In Figure 5, the two-part casing 49 has an internal transverse bearing 50. Short shafts 51 are journaled in the shell of the casing and in the bearingand are provided at 50 their outer ends with arms 52 which are connected by pivoted links 53 with such a mechanism as that shown at 2124 in Figure 1, rotation being derived from the engine shaft, as shown in Figure 1. Large beveled gears 54.54 are secured to the intermediate portions of the shafts 51 and mesh with smaller beveled pinions 55 on tubular shafts 56 journaled in the casing 49 and having heads 57 that bear against the inside of the casing. 50 The shafts 56 have external bolting flanges 58 secured to corresponding flanges 59 on the propeller blades 60. The reinforcing member or rod 61 corresponds to the part 15 of Figure 2 and extends from the butts of the propeller blades through the bearing 50 and other parts that lie between the propeller blades.

This form is used when it is desired to secure a maximum change of pitch with a minimum movement in the operating means. Rotation of the propeller blade for adjustment about an axis at right angles to the driving axis, is brought about by means of the links 53, the arms 52, the shafts 51, and the large beveled gears 54, the gears 54 meshing with the pinions 55, to turn the tubular shafts 56 and the blades 60, according to the desires of the operator.

In Figure 6, the casing is shown at 62 and the internal bearing or bridge at 63. Short shafts 64 are journaled in the shell of the casing and in a bearing 63. Arms 65 are secured to the outer ends of the shafts 64 and are pivoted to links 66 that function like the links 20 of Figure 1, the engine drive being that of Figure 1, if' desired. Large beveled gears 67 are secured to the intermediate portions of the shafts 64, the gears 67 meshing with beveled pinions 68 secured at 69 to a shaft 70 journaled in the bearing 63 and secured at 71, to the butts 72 of the propeller blades 73, the parts 72 being journaled in the casing 62 and having feet 74 that bear against the inside of the casing 62.

The propeller blades 73 are rocked foradjustment, by a-train of parts comprising the links 66, the arms 65, the shafts 64, the beveled gears 67, the beveled pinions 6S, and the shaft 70.

Referring to Figure 1, as typical, it will be understood that by removing the bolts 11, a propeller blade which is damaged, or otherwise. unsuitable for use, may be removed, and be replaced by another in proper condition for service. I

The construction of the device is such that not only may'the pitch of the blades be changed, but, further, a reversal of the blades may be effected. A braking operation therefore may be brought about, to lessen the time required for landing, and to check the force of a downward movement when the plane is out of control, provided, of course, that the engine still is capable of functioning.

In connection with the gears, these elements may be of any desired size, generally stated, or with respect to each other, and I do not limit myself as to proportions in the gears.

What is claimed is:

1. In a device of the class described, a support, tubular shafts journaled in the support, propeller blades connected to the outer ends of the shafts, the shafts being rotatable to change the pitch of the blades, beveled gears connected to the inner ends of the shafts, a

reinforcing member '15 extended across the support, through the gears, and into the tubular shafts, beveled pinions carried for rotation on the support and meshing with the gears, and means under the control of an operator for actuating the pinions.

2. In a device of the class described, a support, propeller blades journaled on the support for rotation about an axis to change the pitch of the blades, shafts disposed approximately at right angles to said axis and journaled on the support, beveled gears forming an operative connection between the shafts and the blades, arms on the shafts, a slide mounted to reciprocate on the support, and links connecting the slide with the arms.

3. In a device of the class described, a support, hollow shafts journaled in the support, propeller blades. connected to the hollow shafts, main shafts secured to the hollow shafts, gears secured to the main shafts, supplemental shafts journaled on the support and disposed parallel to the main shafts, pinions on the supplemental shafts and meshing with the gears, and means under the control of an operatorfor rotating the supplemental shafts. I

4. In a device of the class described, a support, propeller shafts journaled on the support for rotation about a common axis, first gear members, means for connecting the first gear members to the propeller shafts, second gear members meshing with opposite portions of the first gear members, second shafts carrying the second gear members and journaled in the support on'opposite sides of the propeller shafts, arms carried by the second shafts, and operating means connected to the arms, the gear members, the second shafts, and the arms being so located as to produce balance with respect to said axis.

In testimony thatI claim the foregoing as my. own, I have hereto aflixed mv signature.

GUY- THOMAS. 

